IT is now three weeks since Richard Davis was killed by a fall from the chaser Mr Sox at Southwell, but the events and rumours following his death continue to take twist after bizarre twist. Three horses have now died at the stables of Laura Shally, Mr Sox's trainer, since Davis's death on July 19th. And, though Derbyshire police can offer no definite comment until toxicology tests are completed, Shally's vet is convinced that all three were poisoned.

Robin Kernohan, who has treated Shally's team for six months, said that the horses had suffered a "sickening" death, and stated that he believed poison had been put in their drinking water. "The horses' throats are paralysed, they have muscle tremors, sweating and show colic like tendencies," Kernohan said. "They then go into a coma and die." Mr Sox would have become a fourth victim, but the horse drinker supplying him was faulty.

"We are awaiting the full results of forensic and toxicology tests being carried out at a Newmarket laboratory," a spokesman for Derbyshire police said yesterday, and the Jockey Club too will not offer any comment until the cause of death has been determined. It seems likely, however, that a full scale criminal investigation is only a matter of time.

In a separate development, it became clear yesterday that many trainers have reservations about the condition of the course where Davis died. When entries closed for next Tuesday's meeting at Southwell, the first jump meeting at the track since last month's tragedy, not a single event had attracted more than seven contestants, and as a result the entire card was re opened for additional entries.

This is the first time that every race at a meeting has been reopened, with only 29 horses put forward for the six races. The last four hurdle events attracted just four entries each.

The ground at Southwell was criticised last month when the official going was changed to firm after the second race, contrary to assurances that the going would be no faster than good to firm throughout the summer jumps campaign.

While investigations continued into the deaths at Shally's yard, it was also revealed yesterday that a former racehorse, Fisherman's Quay, was attacked with "an axe or machete" last week in the field near Dunbar, East Lothian, where he is spending his retirement after a career in hunter chases and point to points.